/* -------------------------------------------------------------------------
 *
 * pg_control.h
 *      The system control file "pg_control" is not a heap relation.
 *      However, we define it here so that the format is documented.
 *
 *
 * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/catalog/pg_control.h
 *
 * -------------------------------------------------------------------------
 */
#ifndef PG_CONTROL_H
#define PG_CONTROL_H

#include "access/xlogdefs.h"
#include "pgtime.h"                /* for pg_time_t */
#include "utils/pg_crc.h"
#include "port/pg_crc32c.h"


/* Version identifier for this pg_control format */
#define PG_CONTROL_VERSION    923

/*
 * Body of CheckPoint XLOG records.  This is declared here because we keep
 * a copy of the latest one in pg_control for possible disaster recovery.
 * Changing this struct requires a PG_CONTROL_VERSION bump.
 */
typedef struct CheckPoint {
    XLogRecPtr        redo;            /* next RecPtr available when we began to
                                        * create CheckPoint (i.e. REDO start point) */
    TimeLineID        ThisTimeLineID;  /* current TLI */
    bool              fullPageWrites;  /* current full_page_writes */
    TransactionId     nextXid;         /* next free XID */
    Oid               nextOid;         /* next free OID */
    MultiXactId       nextMulti;       /* next free MultiXactId */
    MultiXactOffset   nextMultiOffset; /* next free MultiXact offset */
    TransactionId     oldestXid;       /* cluster-wide minimum datfrozenxid */
    Oid               oldestXidDB;     /* database with minimum datfrozenxid */
    pg_time_t         time;            /* time stamp of checkpoint */
    XLogSegNo         remove_seg;      /*the xlog segno we keep during this checkpoint*/
    /*
     * Oldest XID still running. This is only needed to initialize hot standby
     * mode from an online checkpoint, so we only bother calculating this for
     * online checkpoints and only when wal_level is hot_standby. Otherwise
     * it's set to InvalidTransactionId.
     */
    TransactionId     oldestActiveXid;
} CheckPoint;

/*
 * checkpoint new
 */
typedef struct CheckPointNew {
    CheckPoint ori_checkpoint;
    CommitSeqNo next_csn;
} CheckPointNew;

/* add length to distinguish between different versions of checkpoint */
typedef struct CheckPointPlus
{
    CheckPoint ori_checkpoint;
    CommitSeqNo next_csn;
    uint64 length;
    TransactionId recent_global_xmin;
    /* you can add more attributes here */
} CheckPointPlus;

typedef struct CheckPointUndo
{
    CheckPoint ori_checkpoint;
    CommitSeqNo next_csn;
    uint64 length;
    TransactionId recent_global_xmin;
    uint64 globalRecycleXid;
    /* you can add more attributes here */
} CheckPointUndo;

/* XLOG info values for XLOG rmgr */

#define XLOG_CHECKPOINT_SHUTDOWN        0x00
#define XLOG_CHECKPOINT_ONLINE          0x10
#define XLOG_NOOP                       0x20
#define XLOG_NEXTOID                    0x30
#define XLOG_SWITCH                     0x40
#define XLOG_BACKUP_END                 0x50
#define XLOG_PARAMETER_CHANGE           0x60
#define XLOG_RESTORE_POINT              0x70
#define XLOG_FPW_CHANGE                 0x80
#define XLOG_END_OF_RECOVERY            0x90    /* not use in mppdb*/
#define XLOG_FPI_FOR_HINT               0xA0
#define XLOG_FPI                        0xB0    /* not use in mppdb*/
#define XLOG_DELAY_XLOG_RECYCLE         0xC0

#define XLOG_MERGE_RECORD               0x01

/*
 * System status indicator.  Note this is stored in pg_control; if you change
 * it, you must bump PG_CONTROL_VERSION
 */
typedef enum DBState {
    DB_STARTUP = 0,
    DB_SHUTDOWNED,
    DB_SHUTDOWNED_IN_RECOVERY,
    DB_SHUTDOWNING,
    DB_IN_CRASH_RECOVERY,
    DB_IN_ARCHIVE_RECOVERY,
    DB_IN_PRODUCTION
} DBState;

/*
 * Contents of pg_control.
 *
 * NOTE: try to keep this under 512 bytes so that it will fit on one physical
 * sector of typical disk drives.  This reduces the odds of corruption due to
 * power failure midway through a write.
 */
typedef struct ControlFileData {
    /*
     * Unique system identifier --- to ensure we match up xlog files with the
     * installation that produced them.
     */
    uint64        system_identifier;

    /*
     * Version identifier information.    Keep these fields at the same offset,
     * especially pg_control_version; they won't be real useful if they move
     * around.    (For historical reasons they must be 8 bytes into the file
     * rather than immediately at the front.)
     *
     * pg_control_version identifies the format of pg_control itself.
     * catalog_version_no identifies the format of the system catalogs.
     *
     * There are additional version identifiers in individual files; for
     * example, WAL logs contain per-page magic numbers that can serve as
     * version cues for the WAL log.
     */
    uint32        pg_control_version;        /* PG_CONTROL_VERSION */
    uint32        catalog_version_no;        /* see catversion.h */
    uint32        timeline;

    /*
     * System status data
     */
    DBState        state;            /* see enum above */
    pg_time_t    time;            /* time stamp of last pg_control update */
    XLogRecPtr    checkPoint;        /* last check point record ptr */
    XLogRecPtr    prevCheckPoint; /* previous check point record ptr */

    CheckPoint    checkPointCopy; /* copy of last check point record */

    /*
     * These two values determine the minimum point we must recover up to
     * before starting up:
     *
     * minRecoveryPoint is updated to the latest replayed LSN whenever we
     * flush a data change during archive recovery. That guards against
     * starting archive recovery, aborting it, and restarting with an earlier
     * stop location. If we've already flushed data changes from WAL record X
     * to disk, we mustn't start up until we reach X again. Zero when not
     * doing archive recovery.
     *
     * backupStartPoint is the redo pointer of the backup start checkpoint, if
     * we are recovering from an online backup and haven't reached the end of
     * backup yet. It is reset to zero when the end of backup is reached, and
     * we mustn't start up before that. A boolean would suffice otherwise, but
     * we use the redo pointer as a cross-check when we see an end-of-backup
     * record, to make sure the end-of-backup record corresponds the base
     * backup we're recovering from.
     *
     * backupEndPoint is the backup end location, if we are recovering from an
     * online backup which was taken from the standby and haven't reached the
     * end of backup yet. It is initialized to the minimum recovery point in
     * pg_control which was backed up last. It is reset to zero when the end
     * of backup is reached, and we mustn't start up before that.
     *
     * If backupEndRequired is true, we know for sure that we're restoring
     * from a backup, and must see a backup-end record before we can safely
     * start up. If it's false, but backupStartPoint is set, a backup_label
     * file was found at startup but it may have been a leftover from a stray
     * pg_start_backup() call, not accompanied by pg_stop_backup().
     */
    XLogRecPtr    minRecoveryPoint;
    XLogRecPtr    backupStartPoint;
    XLogRecPtr    backupEndPoint;
    bool        backupEndRequired;

    /*
     * Parameter settings that determine if the WAL can be used for archival
     * or hot standby.
     */
    int            wal_level;
    int            MaxConnections;
    int            max_prepared_xacts;
    int            max_locks_per_xact;

    /*
     * This data is used to check for hardware-architecture compatibility of
     * the database and the backend executable.  We need not check endianness
     * explicitly, since the pg_control version will surely look wrong to a
     * machine of different endianness, but we do need to worry about MAXALIGN
     * and floating-point format.  (Note: storage layout nominally also
     * depends on SHORTALIGN and INTALIGN, but in practice these are the same
     * on all architectures of interest.)
     *
     * Testing just one double value is not a very bulletproof test for
     * floating-point compatibility, but it will catch most cases.
     */
    uint32        maxAlign;        /* alignment requirement for tuples */
    double        floatFormat;    /* constant 1234567.0 */
#define FLOATFORMAT_VALUE    1234567.0

    /*
     * This data is used to make sure that configuration of this database is
     * compatible with the backend executable.
     */
    uint32        blcksz;            /* data block size for this DB */
    uint32        relseg_size;       /* blocks per segment of large relation */

    uint32        xlog_blcksz;       /* block size within WAL files */
    uint32        xlog_seg_size;     /* size of each WAL segment */

    uint32        nameDataLen;       /* catalog name field width */
    uint32        indexMaxKeys;      /* max number of columns in an index */

    uint32        toast_max_chunk_size;    /* chunk size in TOAST tables */

    /* flag indicating internal format of timestamp, interval, time */
    bool          enableIntTimes;    /* int64 storage enabled? */

    /* flags indicating pass-by-value status of various types */
    bool          float4ByVal;       /* float4 pass-by-value? */
    bool          float8ByVal;       /* float8, int8, etc pass-by-value? */

    /* flag indicating bootstrap relations stored in segment or not */
    bool          bootstrap_segment;

    /* CRC of all above ... MUST BE LAST! */
    pg_crc32c     crc;
} ControlFileData;

typedef struct LsnXlogFlushData {
    XLogRecPtr    localLsnFlushPoint;        /* latest flush buffer's lsn postion on primary*/
    XLogRecPtr    peerXlogFlushPoint;        /* flush xlog postion on standby */
    pg_crc32    crc;
} LsnXlogFlushData;

/*
 * Physical size of the pg_control file.  Note that this is considerably
 * bigger than the actually used size (ie, sizeof(ControlFileData)).
 * The idea is to keep the physical size constant independent of format
 * changes, so that ReadControlFile will deliver a suitable wrong-version
 * message instead of a read error if it's looking at an incompatible file.
 */
#define PG_CONTROL_SIZE        8192

#define MIN_INSTANCEID   0
#define MAX_INSTANCEID   63
#define REFORMER_CTL_INSTANCEID (MAX_INSTANCEID + 1)  /* the last page id of pg_control file */
#define INVALID_INSTANCEID -1
#define MAX_INSTANCEID_LEN 3     /* max string len of instance id */ 

#define PG_LSNXLOGFLUSHCHK_FILESIZE        512
extern uint32 get_controlfile_timeline(void);
/*
 * LsnXlogFlushData struct reserved 40 bytes,may be used in the future.
 */
#define PG_LSNXLOGFLUSHCHK_DATASIZE        (40 + 2 * sizeof (XLogRecPtr))

#endif   /* PG_CONTROL_H */

